Here's the deal... I installed a B18C4 last week, and made my own harness.
But now my temp gauge does absolutely nothing.
However...my fan does turn on. I'm puzzled, and not sure how to go about debugging this problem.

Is it a simple matter of hooking up the temp gauge? If so, to what? Wich wire on the firewall? Or does it route through the B18 harness?

Anyone with experience?

 

Check your engine harness. Look for a yel/grn wire in there with a female bullet connector. Hook this up to the temp gage sending unit located under the dizzy. Then you gage will work.

Yel/grn wire starts at the temp gage sending unit, goes to the 8 pin connector on the passenger side shock tower, through the firewall and into the 12 pin connector on the back your gage cluster.



Modified by eda6 at 8:15 AM 4/24/2005

 

I noticed the following.

There are 2 yel/grn wires. 1 of them goes to the fan. 1 goes to the ecu.
My fan seems to work fine... and I have 1 of the wires left over. I assume the fan is switched into the ecu somehow...?

I don't get it.

 

Do a continuity check from this extra wire to the yel/grn wire on the back of your cluster. If you have continuity, then connect the wire to the temp gage sending unit.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SETI20 &raquo;</TD></TR><TR><TD CLASS="quote">I noticed the following.

There are 2 yel/grn wires. 1 of them goes to the fan. 1 goes to the ecu.
My fan seems to work fine... and I have 1 of the wires left over. I assume the fan is switched into the ecu somehow...?

I don't get it.</TD></TR></TABLE>

It has to be, at a certain temperature and running condidions the ecu turns on the fan to cool the engine.

edit- the fan doesn't have a way to determine the temp at which it's supposed to turn on, therefore, the ecu does this.

 

Well....turns out to be quite simple.
The gauge has it's own sensor on the head. Hooks straight into the cluster.
The fan has its own sensor on the thermostat.

The ECU uses the TW sensor to gauge the tempon its own, so you can enable vtec.

Reason my vtec doesn't engage...is because the C4, like the C1, does not have an oil pressure sensor.

D'OH!!! I need more sleep. ...ohyeah...and to have a chip burned with press check turned off.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fast88std &raquo;</TD></TR><TR><TD CLASS="quote">It has to be, at a certain temperature and running condidions the ecu turns on the fan to cool the engine.

edit- the fan doesn't have a way to determine the temp at which it's supposed to turn on, therefore, the ecu does this.</TD></TR></TABLE>

So...the TW sensor tells the ECU to turn on the fan...?
Then what's the sensor on the B18 thermostat for?